What is the value of C++ expression 5 * 4 - 6 * 3 - 9?
What is the value of C++ expression 9/4 + 1?
Function g is defined below. What is the value of expression g(3)?
int g(int n) { if(n > 3) return 0; else return 2*n+3; }Answer
Using function g from the preceding exercise, what is the value of expression g(g(3))?
Suppose that variable y, of type double, already exists and has a value. Write a statement or sequence of statements that (1) creates a variable called frame of type double, and (2) makes frame hold value (y2 - 7y + 4)/9. Be sure to use C++ notation correctly. The expression shown is not in C++ notation, but in standard mathematical notation. Answer
Suppose that variable u has type double, and has already been given a value. Write a statement or statements that create variable m, of type double, and make m hold the absolute value of u. For this exercise, do not use the C++ abs function, or any close relative of it. (The absolute value of 4.0 is 4.0, and the absolute value of -4.0 is 4.0.) Answer
Using your solution to the preceding exercise, write a definition of function absoluteValue(u), where u has type double. It should return the absolute value of u. Answer
You have an integer variable n, which already has a value. Write a C++ statement that creates integer variable y and makes y hold the absolute value of n-1. Use your function absoluteValue to do the absolute value computation. Answer
A contract of a function
Write a C++ definition of function seconds(ms), which takes an integer value ms representing some number of milliseconds (thousandths of a second) and returns a real number that is ms in seconds. For example, seconds(2001) = 2.001. Answer
You have two integer variables n and m each holding a number of milliseconds. Write a C++ statement or sequence of statements that creates variable y, of type double, and makes y hold the number of seconds that is equivalent to n + m milliseconds. Use your function from the preceding problem to do the calculation. Answer
Write a C++ definition of function sum(a, b) that takes two integers a and b and returns the sum a + (a + 1) + (a + 2) + ... + b. For example, sum(9,14) = 9 + 10 + 11 + 12 + 13 + 14. If b < a, then sum(a,b) should return 0. Use a loop to do this.
(Hint. You will need two variables, one to count from a to b and the other to keep track of how many of the sum.)
You are given a function prime(n), which returns true if n is a prime number and false if n is not prime. (Do not write prime; just use it.)
Write a C++ definition of function countprimes(a, b), which returns the number of primes that are greater than or equal to a and less than or equal to b. For example, countprimes(4,11) = 3, since the prime numbers from 4 to 11 are 5, 7 and 11, and there are three of them. Use a loop to do this.
(Hint. You will need two variables, one to count from a to b and the other to keep track of how many of them are prime. Use the prime function to ask whether a number is prime. Keep your definition simple.)